Adapter and syringe for front-loading medical fluid injector

Abstract

Various sealing structures are used in a front-loading injector, for preventing leakage of spilled fluid from an external surface of a syringe into the vicinity of the drive ram. For example, a sealing gasket may be incorporated into the front face of the injector housing, for mating to the rearward circular edge of the cylindrical body of a syringe. Alternatively, sealing and locking functions may be performed by a single structure on the rearward end of the syringe. Further, leakage may be prevented by including a non-planar sealing flange on the syringe, positioned on the syringe forward of the locking structure, or by a two-piece structure, including a syringe and a separate leakage stopping washer for surrounding the syringe to halt the flow of fluid along the exterior of the syringe. (As part of this aspect, or as an independent feature, the syringe may include an annularly discontinuous flange forward of the locking structure, for providing mechanical support for the syringe against the injector.) Alternatively, an iris-like structure may be incorporated into the front surface of the injector, for closing about the syringe upon insertion of the syringe into the injector.

What is claimed is:  
     
       1. A front-loading injector for connection to a syringe for driving a plunger in said syringe forward or rearward to inject fluid out of or draw fluid into said syringe, comprising 
       an injector housing having a front face with an opening therein, said opening permitting an injector ram to pass into and out of said housing to drive a plunger in a syringe mounted to said housing,  
       locking structure surrounding said opening in said housing for mating to and holding a rearwardmost surface of said syringe in position against said front face of said housing, and  
       a resilient sealing gasket surrounding said opening for mating to a rearwardmost surface of said syringe, said sealing gasket being compressible to form a seal against said rearwardmost surface of said syringe to inhibit leakage of fluid from an exterior of said syringe to a vicinity of said opening.  
     
     
       2. The front-loading injector of  claim 1  wherein said sealing gasket has a planar forward surface for engaging a planar rearwardmost surface of said syringe. 
     
     
       3. The front-loading injector of  claim 1  wherein said sealing gasket is annular and disc-shaped. 
     
     
       4. The front-loading injector of  claim 1  wherein said locking structure on said front-loading injector comprises one or more radially extending members, which mate to one or more radially extending members on said syringe. 
     
     
       5. The front-loading injector of  claim 4 , wherein said one or more radially extending members on said front-loading injector comprise radially extending tabs disposed partially annularly about said opening. 
     
     
       6. The front-loading injector of  claim 5 , wherein said tabs form a radially outwardly-facing groove, for receiving a radially inwardly-extending member on said syringe. 
     
     
       7. The front-loading injector of  claim 5 , wherein said tabs from a radially inwardly-facing groove, for receiving a radially outwardly-extending member on said syringe. 
     
     
       8. The front-loading injector of  claim 1 , wherein said locking structure on the injector comprises a slot for receiving radially-outwardly extending members on the syringe, said slot receiving said members by sliding the syringe transversely to an axis of said syringe into engagement with said sealing gasket. 
     
     
       9. The front-loading injector of  claim 1 , wherein said locking structure on the injector comprises a rotating turret, for engaging radially-outwardly extending members on the syringe, said turret being rotatable transversely to an axis of said syringe into engagement with said sealing gasket. 
     
     
       10. A method for connecting a syringe to a front-loading injector for driving a plunger in said syringe forward or rearward to inject fluid out of or draw fluid into said syringe, the injector having a housing front face with an opening therein, said opening permitting an injector ram to pass into and out of said housing to drive a plunger in a syringe mounted to said housing, the method comprising 
       providing a locking structure surrounding said opening in said housing for mating to and holding said syringe in position against said housing front face,  
       providing a resilient sealing gasket surrounding said opening for mating to a rearwardmost surface of said syringe,  
       positioning a syringe into engagement with said locking structure and said sealing gasket to compress said gasket and form a seal between said sealing gasket and a rearwardmost surface of said syringe to inhibit leakage of fluid from an exterior of said syringe to a vicinity of said opening.  
     
     
       11. The method of  claim 10  wherein said sealing gasket has a planar forward surface for engaging to a planar rearwardmost surface of said syringe. 
     
     
       12. The method of  claim 10  wherein said sealing gasket is annular and disc-shaped. 
     
     
       13. The method of  claim 10  wherein said locking structure comprises one or more radially extending members, which mate to one or more radially extending members on said syringe. 
     
     
       14. The method of  claim 11 , wherein said radially extending members comprise one or more radially extending tabs disposed partially annularly about said opening. 
     
     
       15. The method of  claim 14 , wherein said tabs form a radially outwardly-facing groove, for receiving a radially inwardly-extending member on said syringe.